Insulating buildings can lower the cost to heat or cool the interior of the building. Along with exterior walls, other structures such as ceilings and floors may also be insulated. Insulating these structures can be achieved with, for example, spray urethane foam insulative materials or fiber insulative materials.
To achieve a desired insulative material rating for such a ceiling, some methods use a spray foam insulative material that may be more expensive than fiber insulative materials. Unfortunately, high R-value batt or roll insulative material is generally too thick to fit within the framing members of the ceiling to achieve a comparable R-value to the applied spray foam insulative material. Moreover, since most roof trusses are constructed out of 2×4's or 2×6's and typical insulative material in attic area is 6 inches to 12 inches thick, installing batt or roll insulative material in the trusses may be labor intensive and may require techniques that compress portions of the insulative material that therefore decrease the R-value.